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/*
* Copyright (C) 2009 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef _UTILS_BACKUP_HELPERS_H
#define _UTILS_BACKUP_HELPERS_H
#include <utils/Errors.h>
#include <utils/String8.h>
#include <utils/KeyedVector.h>
namespace android {
enum {
BACKUP_HEADER_ENTITY_V1 = 0x61746144, // Data (little endian)
};
typedef struct {
int type; // BACKUP_HEADER_ENTITY_V1
int keyLen; // length of the key name, not including the null terminator
int dataSize; // size of the data, not including the padding, -1 means delete
} entity_header_v1;
struct SnapshotHeader {
int magic0;
int fileCount;
int magic1;
int totalSize;
};
struct FileState {
int modTime_sec;
int modTime_nsec;
int mode;
int size;
int crc32;
int nameLen;
};
struct FileRec {
String8 file;
bool deleted;
FileState s;
};
/**
* Writes the data.
*
* If an error occurs, it poisons this object and all write calls will fail
* with the error that occurred.
*/
class BackupDataWriter
{
public:
BackupDataWriter(int fd);
// does not close fd
~BackupDataWriter();
status_t WriteEntityHeader(const String8& key, size_t dataSize);
/* Note: WriteEntityData will write arbitrary data into the file without
* validation or a previously-supplied header. The full backup implementation
* uses it this way to generate a controlled binary stream that is not
* entity-structured. If the implementation here is changed, either this
* use case must remain valid, or the full backup implementation should be
* adjusted to use some other appropriate mechanism.
*/
status_t WriteEntityData(const void* data, size_t size);
void SetKeyPrefix(const String8& keyPrefix);
private:
explicit BackupDataWriter();
status_t write_padding_for(int n);
int m_fd;
status_t m_status;
ssize_t m_pos;
int m_entityCount;
String8 m_keyPrefix;
};
/**
* Reads the data.
*
* If an error occurs, it poisons this object and all write calls will fail
* with the error that occurred.
*/
class BackupDataReader
{
public:
BackupDataReader(int fd);
// does not close fd
~BackupDataReader();
status_t Status();
status_t ReadNextHeader(bool* done, int* type);
bool HasEntities();
status_t ReadEntityHeader(String8* key, size_t* dataSize);
status_t SkipEntityData(); // must be called with the pointer at the beginning of the data.
ssize_t ReadEntityData(void* data, size_t size);
private:
explicit BackupDataReader();
status_t skip_padding();
int m_fd;
bool m_done;
status_t m_status;
ssize_t m_pos;
ssize_t m_dataEndPos;
int m_entityCount;
union {
int type;
entity_header_v1 entity;
} m_header;
String8 m_key;
};
int back_up_files(int oldSnapshotFD, BackupDataWriter* dataStream, int newSnapshotFD,
char const* const* files, char const* const *keys, int fileCount);
int write_tarfile(const String8& packageName, const String8& domain,
const String8& rootPath, const String8& filePath, BackupDataWriter* outputStream);
class RestoreHelperBase
{
public:
RestoreHelperBase();
~RestoreHelperBase();
status_t WriteFile(const String8& filename, BackupDataReader* in);
status_t WriteSnapshot(int fd);
private:
void* m_buf;
bool m_loggedUnknownMetadata;
KeyedVector<String8,FileRec> m_files;
};
//#define TEST_BACKUP_HELPERS 1
#if TEST_BACKUP_HELPERS
int backup_helper_test_empty();
int backup_helper_test_four();
int backup_helper_test_files();
int backup_helper_test_null_base();
int backup_helper_test_missing_file();
int backup_helper_test_data_writer();
int backup_helper_test_data_reader();
#endif
} // namespace android
#endif // _UTILS_BACKUP_HELPERS_H
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